// 
// Entify project
//  
// Author:
//       Lauri Taimila <lauri@taimila.com>
// 
// Copyright (c) 2010 Lauri Taimila
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using System.Reflection;

namespace Taimila.Entify.Attributes
{
	/// <summary>
	/// StringLenghtValidator can be used to validate that string lenght is in given range.
	/// </summary>
	[AttributeUsage(AttributeTargets.Property)]
	public sealed class StringLengthValidatorAttribute : ValidatorAttribute
	{
		/// <summary>
		/// Minimum allowed length of the string.
		/// </summary>
		private int minimumLength;
		
		/// <summary>
		/// Maximum allowed length of the string.
		/// </summary>
		private int maximumLength;
		
		/// <summary>
		/// Initializes StringLengthValidator. Null is considered as a valid value by this validator!
		/// </summary>
		/// <param name="minLength">
		/// Minimum allowed length of the string. This is inclusive limit. 
		/// Value must be positive integer or zero.<see cref="System.Int32"/>
		/// </param>
		/// <param name="maxLength">
		/// Maximum allowed length of the string. This is inclusive limit. 
		/// Value must be same or larger than the minimum length.<see cref="System.Int32"/>
		/// </param>
		public StringLengthValidatorAttribute(int minLength, int maxLength)
		{
			this.minimumLength = minLength;
			this.maximumLength = maxLength;
		}
		
		/// <summary>
		/// Tests is specified value null. 
		/// </summary>
		/// <param name="property">
		/// Property which value is validated. <see cref="PropertyInfo"/>
		/// </param>
		/// <param name="value">
		/// Value to be validated. <see cref="System.Object"/>
		/// </param>
		/// <returns>
		/// ValidationError or null. <see cref="ValidationError"/>
		/// </returns>
		public override ValidationError ValidateValue(PropertyInfo property, object value)
		{
			if(value == null)
			{
				return null;
			}
			
			if(value is string)
			{
				string val = (string) value;
				if(val.Length >= this.minimumLength && val.Length <= this.maximumLength)
				{
					return null;	
				}
				else
				{
					if(val.Length >= this.minimumLength)
					{
						return new ValidationError(ValidationErrorReason.StringIsTooLong, property, "Value of the property " + property.Name + " is too long.");
					}
					else
					{
						return new ValidationError(ValidationErrorReason.StringIsTooShort, property, "Value of the property " + property.Name + " is too short.");
					}
				}
			}
			else
			{
				throw new ArgumentException("StringLengthValidator can be used only with properties which type is 'System.String'");	
			}
		}
	}
}
